Caption: Saber-toothed cat. Fossil skeleton of a saber- toothed cat, genus Smilodon. This powerful carnivore was close to the size of a large modern tiger, and lived in North and South America during the Upper Pleistocene (about one million years ago). The upper canine teeth of this cat were vast in size, sharp, and shaped like backward-curving daggers. Its skeleton was robust, and it had retractable claws. It was capable of hunting down even the large elephant-like animals of the Pleistocene. Fossilization occurs when an organism is buried and its bodily structures are slowly replaced by minerals such as silica & calcite.